AndroidCommunity: AT&T Galaxy S5 reported to be missing Download Booster feature. http://google.com/newsstand/s/CBIwiNjBqho
Just as well, with a $10 a gigabyte plan, 150 Mbit will render you broke as a joke in hours anyway. I wonder when one of these major carriers will realize that people actually want their home broadband on the go, not an emergency connection? There is something wrong with telcos when everyone I invite over to my place asks for a connection to the WiFi guest network within an hour.